Add mdns module

This allows for CircuitPython to resolve a .local domain and find
other devices with MDNS services.

First step for #6174

locale/circuitpython.pot

@@ -2408,6 +2408,10 @@ msgstr ""
 msgid "Unable to read color palette data"
 msgstr ""
 
+#: ports/espressif/common-hal/mdns/Server.c
+msgid "Unable to start mDNS query"
+msgstr ""
+
 #: shared-bindings/nvm/ByteArray.c
 msgid "Unable to write to nvm."
 msgstr ""
@@ -3625,6 +3629,14 @@ msgstr ""
 msgid "loopback + silent mode not supported by peripheral"
 msgstr ""
 
+#: ports/espressif/common-hal/mdns/Server.c
+msgid "mDNS already initialized"
+msgstr ""
+
+#: ports/espressif/common-hal/mdns/Server.c
+msgid "mDNS only works with built-in WiFi"
+msgstr ""
+
 #: py/parse.c
 msgid "malformed f-string"
 msgstr ""
@@ -4072,6 +4084,7 @@ msgstr ""
 #: ports/espressif/boards/crumpspace_crumps2/mpconfigboard.h
 #: ports/espressif/boards/electroniccats_bastwifi/mpconfigboard.h
 #: ports/espressif/boards/espressif_esp32c3_devkitm_1_n4/mpconfigboard.h
+#: ports/espressif/boards/espressif_esp32s2_devkitc_1_n4/mpconfigboard.h
 #: ports/espressif/boards/espressif_esp32s2_devkitc_1_n4r2/mpconfigboard.h
 #: ports/espressif/boards/espressif_esp32s3_box/mpconfigboard.h
 #: ports/espressif/boards/espressif_esp32s3_devkitc_1_n8/mpconfigboard.h

ports/espressif/CMakeLists.txt

@@ -6,7 +6,7 @@ set(ENV{IDF_PATH} ${CMAKE_SOURCE_DIR}/esp-idf)
 
 # The component list here determines what options we get in menuconfig and what the ninja file
 # can build.
-set(COMPONENTS esptool_py soc driver log main esp-tls mbedtls esp_event esp_adc_cal esp_netif esp_wifi lwip wpa_supplicant freertos bt)
+set(COMPONENTS esptool_py soc driver log main esp-tls mbedtls mdns esp_event esp_adc_cal esp_netif esp_wifi lwip wpa_supplicant freertos bt)
 
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(circuitpython)

ports/espressif/Makefile

@@ -360,7 +360,7 @@ $(HEADER_BUILD)/qstr.split: | $(BUILD)/esp-idf/config/sdkconfig.h
 BINARY_WIFI_BLOBS = libcoexist.a libcore.a libespnow.a libmesh.a libnet80211.a libpp.a libsmartconfig.a libwapi.a
 BINARY_BLOBS = esp-idf/components/esp_phy/lib/$(IDF_TARGET)/libphy.a $(addprefix esp-idf/components/esp_wifi/lib/$(IDF_TARGET)/, $(BINARY_WIFI_BLOBS))
 
-ESP_IDF_COMPONENTS_LINK = $(IDF_TARGET_ARCH) app_update bootloader_support driver efuse esp_adc_cal esp_common esp_event esp_hw_support esp_ipc esp_netif esp_pm esp_phy esp_ringbuf esp_rom esp_system esp_timer esp-tls esp_wifi freertos hal heap log lwip mbedtls newlib nvs_flash pthread soc spi_flash vfs wpa_supplicant
+ESP_IDF_COMPONENTS_LINK = $(IDF_TARGET_ARCH) app_update bootloader_support driver efuse esp_adc_cal esp_common esp_event esp_hw_support esp_ipc esp_netif esp_pm esp_phy esp_ringbuf esp_rom esp_system esp_timer esp-tls esp_wifi freertos hal heap log lwip mbedtls mdns newlib nvs_flash pthread soc spi_flash vfs wpa_supplicant
 ifneq ($(CIRCUITPY_BLEIO),0)
 	ESP_IDF_COMPONENTS_LINK += bt
 	BINARY_BLOBS += esp-idf/components/esp_phy/lib/$(IDF_TARGET)/libbtbb.a \

ports/espressif/boards/espressif_esp32s2_devkitc_1_n4/board.c

@@ -0,0 +1,48 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "supervisor/board.h"
+#include "mpconfigboard.h"
+#include "shared-bindings/microcontroller/Pin.h"
+
+void board_init(void) {
+    // Debug UART
+    #ifdef DEBUG
+    common_hal_never_reset_pin(&pin_GPIO43);
+    common_hal_never_reset_pin(&pin_GPIO44);
+    #endif /* DEBUG */
+}
+
+bool board_requests_safe_mode(void) {
+    return false;
+}
+
+void reset_board(void) {
+
+}
+
+void board_deinit(void) {
+}

ports/espressif/boards/espressif_esp32s2_devkitc_1_n4/mpconfigboard.h

@@ -0,0 +1,39 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+// Micropython setup
+
+#define MICROPY_HW_BOARD_NAME       "ESP32-S2-DevKitC-1-N4"
+#define MICROPY_HW_MCU_NAME         "ESP32S2"
+
+#define MICROPY_HW_NEOPIXEL         (&pin_GPIO18)
+
+#define CIRCUITPY_BOOT_BUTTON       (&pin_GPIO0)
+
+#define DEFAULT_UART_BUS_RX         (&pin_GPIO44)
+#define DEFAULT_UART_BUS_TX         (&pin_GPIO43)
+
+#define BOARD_USER_SAFE_MODE_ACTION translate("pressing boot button at start up.\n")

ports/espressif/boards/espressif_esp32s2_devkitc_1_n4/mpconfigboard.mk

@@ -0,0 +1,17 @@
+USB_VID = 0x303A
+USB_PID = 0x7009
+USB_PRODUCT = "ESP32-S2-DevKitC-1-N4"
+USB_MANUFACTURER = "Espressif"
+
+IDF_TARGET = esp32s2
+
+INTERNAL_FLASH_FILESYSTEM = 1
+LONGINT_IMPL = MPZ
+
+# The default queue depth of 16 overflows on release builds,
+# so increase it to 32.
+CFLAGS += -DCFG_TUD_TASK_QUEUE_SZ=32
+
+CIRCUITPY_ESP_FLASH_MODE=dio
+CIRCUITPY_ESP_FLASH_FREQ=40m
+CIRCUITPY_ESP_FLASH_SIZE=4MB

ports/espressif/boards/espressif_esp32s2_devkitc_1_n4/pins.c

@@ -0,0 +1,53 @@
+#include "shared-bindings/board/__init__.h"
+
+STATIC const mp_rom_map_elem_t board_module_globals_table[] = {
+    CIRCUITPYTHON_BOARD_DICT_STANDARD_ITEMS
+
+    { MP_ROM_QSTR(MP_QSTR_IO0), MP_ROM_PTR(&pin_GPIO0) },
+    { MP_ROM_QSTR(MP_QSTR_IO1), MP_ROM_PTR(&pin_GPIO1) },
+    { MP_ROM_QSTR(MP_QSTR_IO2), MP_ROM_PTR(&pin_GPIO2) },
+    { MP_ROM_QSTR(MP_QSTR_IO3), MP_ROM_PTR(&pin_GPIO3) },
+    { MP_ROM_QSTR(MP_QSTR_IO4), MP_ROM_PTR(&pin_GPIO4) },
+    { MP_ROM_QSTR(MP_QSTR_IO5), MP_ROM_PTR(&pin_GPIO5) },
+    { MP_ROM_QSTR(MP_QSTR_IO6), MP_ROM_PTR(&pin_GPIO6) },
+    { MP_ROM_QSTR(MP_QSTR_IO7), MP_ROM_PTR(&pin_GPIO7) },
+    { MP_ROM_QSTR(MP_QSTR_IO8), MP_ROM_PTR(&pin_GPIO8) },
+    { MP_ROM_QSTR(MP_QSTR_IO9), MP_ROM_PTR(&pin_GPIO9) },
+    { MP_ROM_QSTR(MP_QSTR_IO10), MP_ROM_PTR(&pin_GPIO10) },
+    { MP_ROM_QSTR(MP_QSTR_IO11), MP_ROM_PTR(&pin_GPIO11) },
+    { MP_ROM_QSTR(MP_QSTR_IO12), MP_ROM_PTR(&pin_GPIO12) },
+    { MP_ROM_QSTR(MP_QSTR_IO13), MP_ROM_PTR(&pin_GPIO13) },
+    { MP_ROM_QSTR(MP_QSTR_IO14), MP_ROM_PTR(&pin_GPIO14) },
+    { MP_ROM_QSTR(MP_QSTR_IO15), MP_ROM_PTR(&pin_GPIO15) },
+    { MP_ROM_QSTR(MP_QSTR_IO16), MP_ROM_PTR(&pin_GPIO16) },
+    { MP_ROM_QSTR(MP_QSTR_IO17), MP_ROM_PTR(&pin_GPIO17) },
+
+    { MP_ROM_QSTR(MP_QSTR_NEOPIXEL), MP_ROM_PTR(&pin_GPIO18) },
+    { MP_ROM_QSTR(MP_QSTR_IO18), MP_ROM_PTR(&pin_GPIO18) },
+
+    { MP_ROM_QSTR(MP_QSTR_IO19), MP_ROM_PTR(&pin_GPIO19) },
+    { MP_ROM_QSTR(MP_QSTR_IO20), MP_ROM_PTR(&pin_GPIO20) },
+    { MP_ROM_QSTR(MP_QSTR_IO21), MP_ROM_PTR(&pin_GPIO21) },
+    { MP_ROM_QSTR(MP_QSTR_IO26), MP_ROM_PTR(&pin_GPIO26) },
+    { MP_ROM_QSTR(MP_QSTR_IO33), MP_ROM_PTR(&pin_GPIO33) },
+    { MP_ROM_QSTR(MP_QSTR_IO34), MP_ROM_PTR(&pin_GPIO34) },
+    { MP_ROM_QSTR(MP_QSTR_IO35), MP_ROM_PTR(&pin_GPIO35) },
+    { MP_ROM_QSTR(MP_QSTR_IO36), MP_ROM_PTR(&pin_GPIO36) },
+    { MP_ROM_QSTR(MP_QSTR_IO37), MP_ROM_PTR(&pin_GPIO37) },
+    { MP_ROM_QSTR(MP_QSTR_IO38), MP_ROM_PTR(&pin_GPIO38) },
+    { MP_ROM_QSTR(MP_QSTR_IO39), MP_ROM_PTR(&pin_GPIO39) },
+    { MP_ROM_QSTR(MP_QSTR_IO40), MP_ROM_PTR(&pin_GPIO40) },
+    { MP_ROM_QSTR(MP_QSTR_IO41), MP_ROM_PTR(&pin_GPIO41) },
+    { MP_ROM_QSTR(MP_QSTR_IO42), MP_ROM_PTR(&pin_GPIO42) },
+
+    { MP_ROM_QSTR(MP_QSTR_TX), MP_ROM_PTR(&pin_GPIO43) },
+    { MP_ROM_QSTR(MP_QSTR_IO43), MP_ROM_PTR(&pin_GPIO43) },
+
+    { MP_ROM_QSTR(MP_QSTR_RX), MP_ROM_PTR(&pin_GPIO44) },
+    { MP_ROM_QSTR(MP_QSTR_IO44), MP_ROM_PTR(&pin_GPIO44) },
+
+    { MP_ROM_QSTR(MP_QSTR_IO45), MP_ROM_PTR(&pin_GPIO45) },
+    { MP_ROM_QSTR(MP_QSTR_IO46), MP_ROM_PTR(&pin_GPIO46) },
+
+};
+MP_DEFINE_CONST_DICT(board_module_globals, board_module_globals_table);

ports/espressif/boards/espressif_esp32s2_devkitc_1_n4/sdkconfig

@@ -0,0 +1,5 @@
+#
+# LWIP
+#
+CONFIG_LWIP_LOCAL_HOSTNAME="espressif-esp32s2"
+# end of LWIP

ports/espressif/boards/espressif_esp32s2_devkitc_1_n4r2/mpconfigboard.mk

@@ -1,5 +1,5 @@
-USB_VID = 0x239A
-USB_PID = 0x80A6
+USB_VID = 0x303A
+USB_PID = 0x7009
 USB_PRODUCT = "ESP32-S2-DevKitC-1-N4R2"
 USB_MANUFACTURER = "Espressif"
 

ports/espressif/common-hal/mdns/RemoteService.c

@@ -0,0 +1,52 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "shared-bindings/mdns/RemoteService.h"
+
+const char * common_hal_mdns_remoteservice_get_service_type(mdns_remoteservice_obj_t *self) {
+    return self->result->service_type;
+}
+
+const char * common_hal_mdns_remoteservice_get_protocol(mdns_remoteservice_obj_t *self) {
+    return self->result->proto;
+}
+
+const char * common_hal_mdns_remoteservice_get_instance_name(mdns_remoteservice_obj_t *self) {
+    return self->result->instance_name;
+}
+
+const char * common_hal_mdns_remoteservice_get_hostname(mdns_remoteservice_obj_t *self) {
+    return self->result->hostname;
+}
+
+mp_int_t common_hal_mdns_remoteservice_get_port(mdns_remoteservice_obj_t *self) {
+    return self->result->port;
+}
+
+void common_hal_mdns_remoteservice_deinit(mdns_remoteservice_obj_t *self) {
+    mdns_query_results_free(self->result);
+    self->result = NULL;
+}

ports/espressif/common-hal/mdns/RemoteService.h

@@ -0,0 +1,34 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+#include "components/mdns/include/mdns.h"
+
+typedef struct {
+    mp_obj_base_t base;
+    mdns_result_t *result;
+} mdns_remoteservice_obj_t;

ports/espressif/common-hal/mdns/Server.c

@@ -0,0 +1,149 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "shared-bindings/mdns/Server.h"
+
+#include "py/gc.h"
+#include "py/runtime.h"
+#include "shared-bindings/mdns/RemoteService.h"
+#include "shared-bindings/wifi/__init__.h"
+
+#include "components/mdns/include/mdns.h"
+
+STATIC bool inited = false;
+
+void common_hal_mdns_server_construct(mdns_server_obj_t *self, mp_obj_t network_interface) {
+    if (network_interface != MP_OBJ_FROM_PTR(&common_hal_wifi_radio_obj)) {
+        mp_raise_ValueError(translate("mDNS only works with built-in WiFi"));
+        return;
+    }
+    if (inited) {
+        mp_raise_RuntimeError(translate("mDNS already initialized"));
+    }
+    mdns_init();
+
+    uint8_t mac[6];
+    esp_netif_get_mac(common_hal_wifi_radio_obj.netif, mac);
+    snprintf(self->default_hostname, sizeof(self->default_hostname), "cpy-%02x%02x%02x", mac[3], mac[4], mac[5]);
+    common_hal_mdns_server_set_hostname(self, self->default_hostname);
+
+    // Set a delegated entry to ourselves. This allows us to respond to "circuitpython.local"
+    // queries as well.
+    // TODO: Allow for disabling this with `supervisor.disable_web_workflow()`.
+    mdns_ip_addr_t our_ip;
+    esp_netif_get_ip_info(common_hal_wifi_radio_obj.netif, &common_hal_wifi_radio_obj.ip_info);
+    our_ip.next = NULL;
+    our_ip.addr.type = ESP_IPADDR_TYPE_V4;
+    our_ip.addr.u_addr.ip4 = common_hal_wifi_radio_obj.ip_info.ip;
+    our_ip.addr.u_addr.ip6.addr[1] = 0;
+    our_ip.addr.u_addr.ip6.addr[2] = 0;
+    our_ip.addr.u_addr.ip6.addr[3] = 0;
+    our_ip.addr.u_addr.ip6.zone = 0;
+    mdns_delegate_hostname_add("circuitpython", &our_ip);
+}
+
+void common_hal_mdns_server_deinit(mdns_server_obj_t *self) {
+    inited = false;
+    mdns_free();
+}
+
+bool common_hal_mdns_server_deinited(mdns_server_obj_t *self) {
+    // This returns INVALID_STATE when not initialized and INVALID_PARAM when it
+    // is.
+    return mdns_instance_name_set(NULL) == ESP_ERR_INVALID_STATE;
+}
+
+const char * common_hal_mdns_server_get_hostname(mdns_server_obj_t *self) {
+    return self->hostname;
+}
+
+void common_hal_mdns_server_set_hostname(mdns_server_obj_t *self, const char *hostname) {
+    mdns_hostname_set(hostname);
+    self->hostname = hostname;
+}
+
+const char * common_hal_mdns_server_get_instance_name(mdns_server_obj_t *self) {
+    if (self->instance_name == NULL) {
+        return self->hostname;
+    }
+    return self->instance_name;
+}
+
+void common_hal_mdns_server_set_instance_name(mdns_server_obj_t *self, const char *instance_name) {
+    mdns_instance_name_set(instance_name);
+    self->instance_name = instance_name;
+}
+
+mp_obj_t common_hal_mdns_server_find(mdns_server_obj_t *self, const char *service_type, const char *protocol, mp_float_t timeout) {
+    mdns_search_once_t *search = mdns_query_async_new(NULL, service_type, protocol, MDNS_TYPE_PTR, timeout * 1000, 255, NULL);
+    if (search == NULL) {
+        mp_raise_RuntimeError(translate("Unable to start mDNS query"));
+    }
+    mdns_result_t *results;
+    while (!mdns_query_async_get_results(search, 1, &results)) {
+        RUN_BACKGROUND_TASKS;
+    }
+    mdns_query_async_delete(search);
+    // Count how many results we got.
+    // TODO: Remove this loop when moving off 4.4. Newer APIs will give us num_results
+    // back directly.
+    mdns_result_t *next = results;
+    uint8_t num_results = 0;
+    while (next != NULL) {
+        num_results++;
+        next = next->next;
+    }
+    mp_obj_tuple_t *tuple = MP_OBJ_TO_PTR(mp_obj_new_tuple(num_results, NULL));
+    next = results;
+    // Don't error if we're out of memory. Instead, truncate the tuple.
+    uint8_t added = 0;
+    while (next != NULL) {
+        mdns_remoteservice_obj_t *service = gc_alloc(sizeof(mdns_remoteservice_obj_t), true, false);
+        if (service == NULL) {
+            if (added == 0) {
+                m_malloc_fail(sizeof(mdns_remoteservice_obj_t));
+            }
+            // Free the remaining results from the IDF because we don't have
+            // enough space in Python.
+            mdns_query_results_free(next);
+            break;
+        }
+        service->result = next;
+        service->base.type = &mdns_remoteservice_type;
+        next = next->next;
+        // Break the linked list so we free each result separately.
+        service->result->next = NULL;
+        tuple->items[added] = MP_OBJ_FROM_PTR(service);
+        added++;
+    }
+    tuple->len = added;
+
+    return MP_OBJ_FROM_PTR(tuple);
+}
+
+void common_hal_mdns_server_advertise_service(mdns_server_obj_t *self, const char *service_type, const char *protocol, mp_int_t port) {
+    mdns_service_add(NULL, service_type, protocol, port, NULL, 0);
+}

ports/espressif/common-hal/mdns/Server.h

@@ -0,0 +1,37 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+#include "py/obj.h"
+
+typedef struct {
+    mp_obj_base_t base;
+    const char *hostname;
+    const char *instance_name;
+    // "cpy-" "XXXXXX" "\0"
+    char default_hostname[4 + 6 + 1];
+} mdns_server_obj_t;

ports/espressif/common-hal/mdns/__init__.c

@@ -0,0 +1 @@
+// No mdns module functions.

ports/espressif/common-hal/wifi/Radio.c

@@ -42,6 +42,10 @@
 #include "components/esp_wifi/include/esp_wifi.h"
 #include "components/lwip/include/apps/ping/ping_sock.h"
 
+#if CIRCUITPY_MDNS
+#include "components/mdns/include/mdns.h"
+#endif
+
 #define MAC_ADDRESS_LENGTH 6
 
 static void set_mode_station(wifi_radio_obj_t *self, bool state) {
@@ -91,6 +95,9 @@ void common_hal_wifi_radio_set_enabled(wifi_radio_obj_t *self, bool enabled) {
         if (self->current_scan != NULL) {
             common_hal_wifi_radio_stop_scanning_networks(self);
         }
+        #if CIRCUITPY_MDNS
+        mdns_free();
+        #endif
         ESP_ERROR_CHECK(esp_wifi_stop());
         self->started = false;
         return;

py/circuitpy_defns.mk

@@ -214,6 +214,9 @@ endif
 ifeq ($(CIRCUITPY_MICROCONTROLLER),1)
 SRC_PATTERNS += microcontroller/%
 endif
+ifeq ($(CIRCUITPY_MDNS),1)
+SRC_PATTERNS += mdns/%
+endif
 ifeq ($(CIRCUITPY_NEOPIXEL_WRITE),1)
 SRC_PATTERNS += neopixel_write/%
 endif
@@ -401,6 +404,9 @@ SRC_COMMON_HAL_ALL = \
 	microcontroller/Pin.c \
 	microcontroller/Processor.c \
 	microcontroller/__init__.c \
+	mdns/__init__.c \
+	mdns/Server.c \
+	mdns/RemoteService.c \
 	neopixel_write/__init__.c \
 	nvm/ByteArray.c \
 	nvm/__init__.c \

py/circuitpy_mpconfig.mk

@@ -263,6 +263,9 @@ CFLAGS += -DCIRCUITPY_MEMORYMONITOR=$(CIRCUITPY_MEMORYMONITOR)
 CIRCUITPY_MICROCONTROLLER ?= 1
 CFLAGS += -DCIRCUITPY_MICROCONTROLLER=$(CIRCUITPY_MICROCONTROLLER)
 
+CIRCUITPY_MDNS ?= $(CIRCUITPY_WIFI)
+CFLAGS += -DCIRCUITPY_MDNS=$(CIRCUITPY_MDNS)
+
 CIRCUITPY_MSGPACK ?= $(CIRCUITPY_FULL_BUILD)
 CFLAGS += -DCIRCUITPY_MSGPACK=$(CIRCUITPY_MSGPACK)
 

shared-bindings/mdns/RemoteService.c

@@ -0,0 +1,157 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Dan Halbert for Adafruit Industries
+ * Copyright (c) 2018 Artur Pacholec
+ * Copyright (c) 2017 Glenn Ruben Bakke
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <string.h>
+
+#include "py/objproperty.h"
+#include "py/runtime.h"
+#include "shared-bindings/mdns/RemoteService.h"
+
+//| class RemoteService:
+//|     """Encapsulates information about a remote service that was found during a query. This
+//|     object may only be created by a `mdns.Server`. It has no user-visible constructor."""
+//|
+
+//|     def __init__(self) -> None:
+//|         """Cannot be instantiated directly. Use `mdns.Server.query`."""
+//|         ...
+//|
+
+//|     hostname: str
+//|     """The hostname of the device (read-only),."""
+//|
+STATIC mp_obj_t mdns_remoteservice_get_hostname(mp_obj_t self_in) {
+    mdns_remoteservice_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    const char *hostname = common_hal_mdns_remoteservice_get_hostname(self);
+    return mp_obj_new_str(hostname, strlen(hostname));
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(mdns_remoteservice_get_hostname_obj, mdns_remoteservice_get_hostname);
+
+const mp_obj_property_t mdns_remoteservice_hostname_obj = {
+    .base.type = &mp_type_property,
+    .proxy = { (mp_obj_t)&mdns_remoteservice_get_hostname_obj,
+               MP_ROM_NONE,
+               MP_ROM_NONE },
+};
+
+//|     instance_name: str
+//|     """The human readable instance name for the service. (read-only)"""
+//|
+STATIC mp_obj_t remoteservice_get_instance_name(mp_obj_t self_in) {
+    mdns_remoteservice_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    const char *instance_name = common_hal_mdns_remoteservice_get_instance_name(self);
+    return mp_obj_new_str(instance_name, strlen(instance_name));
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(mdns_remoteservice_get_instance_name_obj, remoteservice_get_instance_name);
+
+const mp_obj_property_t mdns_remoteservice_instance_name_obj = {
+    .base.type = &mp_type_property,
+    .proxy = { (mp_obj_t)&mdns_remoteservice_get_instance_name_obj,
+               MP_ROM_NONE,
+               MP_ROM_NONE },
+};
+
+//|     service_type: str
+//|     """The service type string such as ``_http``. (read-only)"""
+//|
+STATIC mp_obj_t remoteservice_get_service_type(mp_obj_t self_in) {
+    mdns_remoteservice_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    const char *service_type = common_hal_mdns_remoteservice_get_service_type(self);
+    return mp_obj_new_str(service_type, strlen(service_type));
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(mdns_remoteservice_get_service_type_obj, remoteservice_get_service_type);
+
+const mp_obj_property_t mdns_remoteservice_service_type_obj = {
+    .base.type = &mp_type_property,
+    .proxy = { (mp_obj_t)&mdns_remoteservice_get_service_type_obj,
+               MP_ROM_NONE,
+               MP_ROM_NONE },
+};
+
+//|     protocol: str
+//|     """The protocol string such as ``_tcp``. (read-only)"""
+//|
+STATIC mp_obj_t remoteservice_get_protocol(mp_obj_t self_in) {
+    mdns_remoteservice_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    const char *protocol = common_hal_mdns_remoteservice_get_protocol(self);
+    return mp_obj_new_str(protocol, strlen(protocol));
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(mdns_remoteservice_get_protocol_obj, remoteservice_get_protocol);
+
+const mp_obj_property_t mdns_remoteservice_protocol_obj = {
+    .base.type = &mp_type_property,
+    .proxy = { (mp_obj_t)&mdns_remoteservice_get_protocol_obj,
+               MP_ROM_NONE,
+               MP_ROM_NONE },
+};
+
+//|     port: int
+//|     """Port number used for the service. (read-only)"""
+//|
+STATIC mp_obj_t remoteservice_get_port(mp_obj_t self_in) {
+    mdns_remoteservice_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    return MP_OBJ_NEW_SMALL_INT(common_hal_mdns_remoteservice_get_port(self));
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(mdns_remoteservice_get_port_obj, remoteservice_get_port);
+
+const mp_obj_property_t mdns_remoteservice_port_obj = {
+    .base.type = &mp_type_property,
+    .proxy = { (mp_obj_t)&mdns_remoteservice_get_port_obj,
+               MP_ROM_NONE,
+               MP_ROM_NONE },
+};
+
+//|     def __del__(self) -> None:
+//|         """Deletes the RemoteService object."""
+//|         ...
+//|
+STATIC mp_obj_t mdns_remoteservice_obj_deinit(mp_obj_t self_in) {
+    mdns_remoteservice_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_mdns_remoteservice_deinit(self);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(mdns_remoteservice_deinit_obj, mdns_remoteservice_obj_deinit);
+
+STATIC const mp_rom_map_elem_t mdns_remoteservice_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_hostname),       MP_ROM_PTR(&mdns_remoteservice_hostname_obj) },
+    { MP_ROM_QSTR(MP_QSTR_instance_name),  MP_ROM_PTR(&mdns_remoteservice_instance_name_obj) },
+    { MP_ROM_QSTR(MP_QSTR_ipv4_address),   MP_ROM_PTR(&mdns_remoteservice_instance_name_obj) },
+    { MP_ROM_QSTR(MP_QSTR_service_type),   MP_ROM_PTR(&mdns_remoteservice_service_type_obj) },
+    { MP_ROM_QSTR(MP_QSTR_protocol),       MP_ROM_PTR(&mdns_remoteservice_protocol_obj) },
+    { MP_ROM_QSTR(MP_QSTR_port),           MP_ROM_PTR(&mdns_remoteservice_port_obj) },
+
+    { MP_ROM_QSTR(MP_QSTR___del__),        MP_ROM_PTR(&mdns_remoteservice_deinit_obj) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(mdns_remoteservice_locals_dict, mdns_remoteservice_locals_dict_table);
+
+const mp_obj_type_t mdns_remoteservice_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_RemoteService,
+    .locals_dict = (mp_obj_dict_t *)&mdns_remoteservice_locals_dict
+};

shared-bindings/mdns/RemoteService.h

@@ -0,0 +1,41 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Dan Halbert for Adafruit Industries
+ * Copyright (c) 2018 Artur Pacholec
+ * Copyright (c) 2017 Glenn Ruben Bakke
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+#include "py/obj.h"
+#include "common-hal/mdns/RemoteService.h"
+
+extern const mp_obj_type_t mdns_remoteservice_type;
+
+const char * common_hal_mdns_remoteservice_get_service_type(mdns_remoteservice_obj_t *self);
+const char * common_hal_mdns_remoteservice_get_protocol(mdns_remoteservice_obj_t *self);
+const char * common_hal_mdns_remoteservice_get_instance_name(mdns_remoteservice_obj_t *self);
+const char * common_hal_mdns_remoteservice_get_hostname(mdns_remoteservice_obj_t *self);
+mp_int_t common_hal_mdns_remoteservice_get_port(mdns_remoteservice_obj_t *self);
+void common_hal_mdns_remoteservice_deinit(mdns_remoteservice_obj_t *self);

shared-bindings/mdns/Server.c

@@ -0,0 +1,214 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018 Dan Halbert for Adafruit Industries
+ * Copyright (c) 2018 Artur Pacholec
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <string.h>
+
+#include "py/objproperty.h"
+#include "py/runtime.h"
+#include "shared-bindings/mdns/__init__.h"
+#include "shared-bindings/mdns/Server.h"
+#include "shared-bindings/util.h"
+
+//| class Server:
+//|     """The MDNS Server responds to queries for this device's information and allows for querying
+//|        other devices."""
+//|
+
+//|     def __init__(self, network_interface: wifi.Radio) -> None:
+//|         """
+//|         Constructs or returns the mdns.Server for the given network_interface. (CircuitPython
+//|         may already be using it.) Only native interfaces are currently supported.
+//|         """
+//|         ...
+//|
+STATIC mp_obj_t mdns_server_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
+    enum { ARG_network_interface };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_network_interface, MP_ARG_REQUIRED | MP_ARG_OBJ },
+    };
+
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    mdns_server_obj_t *self = m_new_obj(mdns_server_obj_t);
+    self->base.type = &mdns_server_type;
+    common_hal_mdns_server_construct(self, args[ARG_network_interface].u_obj);
+
+    return MP_OBJ_FROM_PTR(self);
+}
+
+//|     def deinit(self) -> None:
+//|         """Stops the server"""
+//|         ...
+//|
+STATIC mp_obj_t mdns_server_obj_deinit(mp_obj_t self_in) {
+    mdns_server_obj_t *self = (mdns_server_obj_t *)self_in;
+    common_hal_mdns_server_deinit(self);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(mdns_server_deinit_obj, mdns_server_obj_deinit);
+
+STATIC void check_for_deinit(mdns_server_obj_t *self) {
+    if (common_hal_mdns_server_deinited(self)) {
+        raise_deinited_error();
+    }
+}
+
+//|
+//|     hostname: str
+//|     """Hostname resolvable as ``<hostname>.local`` in addition to ``circuitpython.local``. Make
+//|        sure this is unique across all devices on the network. It defaults to ``cpy-######``
+//|        where ``######`` is the hex digits of the last three bytes of the mac address."""
+//|
+STATIC mp_obj_t mdns_server_get_hostname(mp_obj_t self) {
+    check_for_deinit(self);
+    const char *hostname = common_hal_mdns_server_get_hostname(self);
+    return mp_obj_new_str(hostname, strlen(hostname));
+}
+MP_DEFINE_CONST_FUN_OBJ_1(mdns_server_get_hostname_obj, mdns_server_get_hostname);
+
+static mp_obj_t mdns_server_set_hostname(mp_obj_t self, mp_obj_t hostname) {
+    check_for_deinit(self);
+    common_hal_mdns_server_set_hostname(self, mp_obj_str_get_str(hostname));
+
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(mdns_server_set_hostname_obj, mdns_server_set_hostname);
+
+const mp_obj_property_t mdns_server_hostname_obj = {
+    .base.type = &mp_type_property,
+    .proxy = { (mp_obj_t)&mdns_server_get_hostname_obj,
+               (mp_obj_t)&mdns_server_set_hostname_obj,
+               MP_ROM_NONE },
+};
+
+//|     instance_name: str
+//|     """Human readable name to describe the device."""
+//|
+STATIC mp_obj_t mdns_server_get_instance_name(mp_obj_t self) {
+    check_for_deinit(self);
+    const char *instance_name = common_hal_mdns_server_get_instance_name(self);
+    return mp_obj_new_str(instance_name, strlen(instance_name));
+}
+MP_DEFINE_CONST_FUN_OBJ_1(mdns_server_get_instance_name_obj, mdns_server_get_instance_name);
+
+STATIC mp_obj_t mdns_server_set_instance_name(mp_obj_t self, mp_obj_t new_instance_name) {
+    check_for_deinit(self);
+    common_hal_mdns_server_set_instance_name(self, mp_obj_str_get_str(new_instance_name));
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(mdns_server_set_instance_name_obj, mdns_server_set_instance_name);
+
+const mp_obj_property_t mdns_server_instance_name_obj = {
+    .base.type = &mp_type_property,
+    .proxy = { (mp_obj_t)&mdns_server_get_instance_name_obj,
+               (mp_obj_t)&mdns_server_set_instance_name_obj,
+               MP_ROM_NONE },
+};
+
+
+//|     def find(self, service_type: str, protocol: str, *, timeout: float = 1) -> Tuple[RemoteService]:
+//|         """Find all locally available remote services with the given service type and protocol.
+//|
+//|         This doesn't allow for direct hostname lookup. To do that, use
+//|         `socketpool.SocketPool.getaddrinfo()`
+//|
+//|         :param str service_type: The service type such as "_http"
+//|         :param str protocol: The service protocol such as "_tcp"
+//|         :param float/int timeout: Time to wait for responses"""
+//|         ...
+//|
+STATIC mp_obj_t mdns_server_find(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    mdns_server_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
+    check_for_deinit(self);
+
+    enum { ARG_service_type, ARG_protocol, ARG_timeout };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_service_type, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_OBJ },
+        { MP_QSTR_protocol, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_OBJ },
+        { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NEW_SMALL_INT(1)} },
+    };
+
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    mp_float_t timeout = mp_obj_get_float(args[ARG_timeout].u_obj);
+    const char *service_type = mp_obj_str_get_str(args[ARG_service_type].u_obj);
+    const char *protocol = mp_obj_str_get_str(args[ARG_protocol].u_obj);
+
+    return common_hal_mdns_server_find(self, service_type, protocol, timeout);
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_KW(mdns_server_find_obj, 1, mdns_server_find);
+
+//|     def advertise_service(self, *,  service_type: str, protocol: str, port: int) -> None:
+//|         """Respond to queries for the given service with the given port.
+//|
+//|         :param str service_type: The service type such as "_http"
+//|         :param str protocol: The service protocol such as "_tcp"
+//|         :param int port: The port used by the service"""
+//|         ...
+//|
+STATIC mp_obj_t mdns_server_advertise_service(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    mdns_server_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
+    check_for_deinit(self);
+
+    enum { ARG_service_type, ARG_protocol, ARG_port };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_service_type, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_OBJ },
+        { MP_QSTR_protocol, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_OBJ },
+        { MP_QSTR_port, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT },
+    };
+
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    const char *service_type = mp_obj_str_get_str(args[ARG_service_type].u_obj);
+    const char *protocol = mp_obj_str_get_str(args[ARG_protocol].u_obj);
+
+    common_hal_mdns_server_advertise_service(self, service_type, protocol, args[ARG_port].u_int);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_KW(mdns_server_advertise_service_obj, 1, mdns_server_advertise_service);
+
+STATIC const mp_rom_map_elem_t mdns_server_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_hostname),          MP_ROM_PTR(&mdns_server_hostname_obj) },
+    { MP_ROM_QSTR(MP_QSTR_instance_name),     MP_ROM_PTR(&mdns_server_instance_name_obj) },
+
+    { MP_ROM_QSTR(MP_QSTR_find),              MP_ROM_PTR(&mdns_server_find_obj) },
+    { MP_ROM_QSTR(MP_QSTR_advertise_service), MP_ROM_PTR(&mdns_server_advertise_service_obj) },
+
+    { MP_ROM_QSTR(MP_QSTR_deinit),            MP_ROM_PTR(&mdns_server_deinit_obj) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(mdns_server_locals_dict, mdns_server_locals_dict_table);
+
+const mp_obj_type_t mdns_server_type = {
+    .base = { &mp_type_type },
+    .name = MP_QSTR_Server,
+    .make_new = mdns_server_make_new,
+    .locals_dict = (mp_obj_t)&mdns_server_locals_dict,
+};

shared-bindings/mdns/Server.h

@@ -0,0 +1,43 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+#include <stdbool.h>
+
+#include "common-hal/mdns/Server.h"
+
+extern const mp_obj_type_t mdns_server_type;
+
+void common_hal_mdns_server_construct(mdns_server_obj_t *self, mp_obj_t network_interface);
+void common_hal_mdns_server_deinit(mdns_server_obj_t *self);
+bool common_hal_mdns_server_deinited(mdns_server_obj_t *self);
+const char * common_hal_mdns_server_get_hostname(mdns_server_obj_t *self);
+void common_hal_mdns_server_set_hostname(mdns_server_obj_t *self, const char *hostname);
+const char * common_hal_mdns_server_get_instance_name(mdns_server_obj_t *self);
+void common_hal_mdns_server_set_instance_name(mdns_server_obj_t *self, const char *instance_name);
+mp_obj_t common_hal_mdns_server_find(mdns_server_obj_t *self, const char *service_type, const char *protocol, mp_float_t timeout);
+void common_hal_mdns_server_advertise_service(mdns_server_obj_t *self, const char *service_type, const char *protocol, mp_int_t port);

shared-bindings/mdns/__init__.c

@@ -0,0 +1,56 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Dan Halbert for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdarg.h>
+
+#include "py/objexcept.h"
+#include "py/runtime.h"
+#include "shared-bindings/mdns/__init__.h"
+#include "shared-bindings/mdns/Server.h"
+#include "shared-bindings/mdns/RemoteService.h"
+
+//| """Multicast Domain Name Service
+//|
+//| The `mdns` module provides basic support for multicast domain name services.
+//| Basic use provides hostname resolution under the .local TLD. This module
+//| also supports DNS Service Discovery that allows for discovering other hosts
+//| that provide a desired service."""
+//|
+
+STATIC const mp_rom_map_elem_t mdns_module_globals_table[] = {
+    { MP_ROM_QSTR(MP_QSTR___name__),             MP_ROM_QSTR(MP_QSTR_mdns) },
+    { MP_ROM_QSTR(MP_QSTR_Server),               MP_ROM_PTR(&mdns_server_type) },
+    { MP_ROM_QSTR(MP_QSTR_RemoteService),        MP_ROM_PTR(&mdns_remoteservice_type) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(mdns_module_globals, mdns_module_globals_table);
+
+const mp_obj_module_t mdns_module = {
+    .base = { &mp_type_module },
+    .globals = (mp_obj_dict_t *)&mdns_module_globals,
+};
+
+MP_REGISTER_MODULE(MP_QSTR_mdns, mdns_module, CIRCUITPY_MDNS);

shared-bindings/mdns/__init__.h

@@ -0,0 +1,27 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once

tools/ci_check_duplicate_usb_vid_pid.py

@@ -51,6 +51,7 @@ DEFAULT_IGNORELIST = [
     "unexpectedmaker_feathers2_prerelease",
     "espressif_kaluga_1",
     "espressif_kaluga_1.3",
+    "espressif_esp32s2_devkitc_1_n4",
     "espressif_esp32s2_devkitc_1_n4r2",
     "espressif_esp32s3_devkitc_1_n8",
     "espressif_esp32s3_devkitc_1_n8r2",